U.K. retirement plans continue to reduce exposure to riskier assets as part of their efforts to derisk, according to an Aon Hewitt survey.

The survey, which is completed every two years, recorded responses from 185 U.K. plans representing £500 billion ($637 billion) in assets. Regarding asset allocation, the survey found that 47% of respondents had reduced exposure to U.K. equities in the past 12 months, with 49% leaving their allocation unchanged; just 4% increased exposure.

Overseas equities exposure was also reduced by 41% of respondents, while the same proportion left their allocation unchanged. The remaining 18% increased allocations to overseas equities.

The biggest increase in the proportion of asset allocation was to liability-driven investing strategies, with 45% of respondents increasing over the past year. Only 3% reduced their allocations to these strategies, while the remaining 52% left it unchanged.

Alternatives and illiquids also saw a large increase in allocations, by 32% and 24%, respectively.

The proportion of retirement plans that are now frozen hit 53% in the 2017 survey, up from 45% in the 2015 survey. The survey said those that remain open to accruals have generally reduced benefits.

The survey also focused on implementation of integrated risk management by plans, as introduced as a focus by The Pensions Regulator in late 2015. It found that 4% of respondents had implemented an integrated risk management plan with actions, and 46% either had no plan or had not documented it. Matthew Arends, partner at Aon Hewitt, said in a news release accompanying the survey that this is despite this year's Pensions Regulator's annual funding statement stating that "all schemes need to put contingency plans in place," and that this plan needs to be agreed with the sponsoring employer in advance and be legally enforceable.

The survey also found plans have focused increasingly on currency risk since the 2015 survey. The survey showed a reduction of 12% in the number of plans having no policy on currency hedging, down to 23%; and an increase of 18% in the number that have or will hedge overseas currency exposure at fair value levels, growing to 42% of respondents.